A game

American  

Or A-game,

noun

Informal.

1. a person’s best effort, abilities, or achievement.

   The candidate brought her A game to the debate.

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'A' game British  

noun

1. informal one's best possible performance, esp in the phrase to bring or take one's 'A' game

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Etymology

Origin of A game

In reference to a sports contest, with the letter A indicating peak performance

Example Sentences

Mattel sells a game called Pictionary vs.

From Los Angeles Times

Former Australia coach Darren Lehmann said England should have "had a better back-up plan" if they think "have made the wrong call" with Bashir but he deserves a game with the Ashes lost.

From BBC

Since then, Travis has worked as a game show host, an actor and an executive producer.

From BBC

Mavericks prodigy Cooper Flagg once again stole the show, with the gifted 19-year-old No.1 draft pick scoring a game high 33 points with nine rebounds and nine assists.

From Barron's

Ellyes Skhiri headed in an early opener and FC Copenhagen winger Achouri then scored twice either side of half-time in a game played in relentless rain in Rabat.

From Barron's